My aunt brings this to every family potluck in May. The creamy cheesy pull when you scoop it out gets everyone asking for the recipe.

Spray the inside of a 6-quart slow cooker lightly with nonstick cooking spray or rub with a little butter to help prevent sticking and make cleanup easier.
Spread the uncooked egg noodles evenly in the bottom of the slow cooker. Don’t pack them down too tightly; a loose, even layer helps them cook more evenly.

In a large bowl or measuring pitcher, whisk together the whole milk, heavy cream, and kosher salt until the salt is dissolved and the mixture looks smooth. This is your simple creamy base that will cook the noodles and create the sauce.
Pour the milk and cream mixture evenly over the dry noodles in the slow cooker. Gently press down on the noodles with the back of a spoon so they’re mostly submerged in the liquid. It’s fine if a few edges stick up; they’ll catch a little color as they cook.
Sprinkle 3 cups of the shredded Swiss cheese evenly over the top of the noodles and cream mixture. Try to cover the surface so you get a nice, melty blanket of cheese as it cooks.

Cover the slow cooker with the lid and cook on LOW for 2 1/2 to 3 hours, or until the noodles are tender but not mushy and most of the liquid has thickened into a creamy sauce. Avoid lifting the lid in the first 2 hours so the noodles cook evenly and the sauce can set up.
Once the noodles are tender, remove the lid and gently stir from the edges toward the center to pull some of the creamy sauce up from the bottom and loosen any noodles that may be sticking. Taste and add a pinch more salt if needed.

Sprinkle the remaining 1 cup of shredded Swiss cheese over the top of the noodles. Cover again and cook on HIGH for 15 to 20 minutes, just until the cheese on top is fully melted and stretchy.
For golden brown edges and a lightly toasted top, carefully transfer the ceramic slow cooker insert (only if it is oven-safe—check your manual) to the oven and broil on the top rack for 2 to 3 minutes, watching closely so it doesn’t burn. This step is optional but gives that classic potluck look with browned cheese at the edges.

Let the noodle bake sit, uncovered, for about 10 minutes before serving. This rest time helps the creamy sauce settle slightly so you still get that lovely cheese pull when you scoop, but it’s not runny. Serve straight from the slow cooker on the warm setting to keep it creamy and melty for your guests.
Variations & Tips